ABSTRACT
Th ere are changes in the immune system and the responsiveness of the system slows with advancing age. It is suggested that dysregulation of cytokines plays a signifi cant role in this alteration of the immune response. Here the role of some cytokines in mortality, longevity, and in two clinical conditions with high prevalence in elderly population, frailty and delirium, is presented and discussed. Th e levels of IL-6 and possibly of TNF-α increase with age, while the levels of IL-2 decrease. Similarly, high levels of IL-6 and perhaps of TNF-α are associated with mortality. However, genetic studies have produced confl icting results regarding longevity and cytokines. Furthermore, there is evidence that frailty, which is characterized by weight loss, low activity, functional decline, slow motor performance and cognitive decline, is associated with high levels of IL-1α, IL-6 and TNF-α. Finally, in delirium, which is oft en caused by infections and frequently is a side eff ect of therapeutic use of cytokines, a close relationship is expected with cytokines. However, only few studies have investigated this relationship and the results are contradictory. Despite the confl icting results, it seems that levels of cytokines change with age, elevated levels of pro-infl ammatory cytokines are associated with frailty in older adults, and they possibly have a direct eff ect in cognitive and functional decline, while their relationship with delirium needs to be further evaluated. Th e mechanisms of the above eff ects are not fully understood and further studies,
preferably longitudinal and in groups of cytokines, are needed to elucidate those mechanisms.
